Production of cellulose derivative products



F'atented June 11; 193 it V- l V -UNITED[ TA E PAT-Est; OFFICE whichis-a non solvent tor-the"cellulosefderivatiye bathsubsequentlyintroduced as before.

PRODUCTIONOF oELnuLosE bERivATIvE" rltonnors 3 h t sn i y iis ominee NoDr'awing} -Application July22, 1931, Serial 7 'No."552,54 6.- In Great Britain July 30,1930 I Y soleims." -(C l.'18; 54) m t V This invention relates to the production of The bath used for the purpose of the present filaments; yarns, threads, ribbons films fiend inv nuenma' difier somewhatiii specific grava'other products from solutions of cellulose ace-p ity rrcm the spinning solution itself; so that the tents or other-cellulose estersor'ethers; filaments or other produe'ts may' ri'se' or fall 5 According tothe present invention solutions through the liquid in ouestion, thus facilitating o f cellulose acetate or other cellulose esters or starting up. Alternatively or in addition the ethers arespun into-a" liquid ofsuch constituspmumg may be started with a bath adapted 'tion-that little ornone of the solventqcontained to coagulate the spinning solution, and the bath in the-spim1ing=solution is removed from'the el iai'iicteris'tic of the present invention subse- 10 filaments or other formed products or at least quently introducedso awed-surround the spin- 0 the filaments or other products 'ori leaving the nine nozzle-"Again when--the subsequent set- 'bath are liquidor substantially--1iquid.- Prefertins of the filaments is tog-be efie'cted'by dry ably the cellulose acetatesolution or solution methods the spinning may be started up by of other ester-orether is extruded into a liduid any suitable method for dry spinning, and the "and for tlie' solvent-of thespinning solution; The 'leng'th of the preliminary bath of water, Water oraque'ous l iquids ingeneral are very hydrocarbon or other-liquid inwhich the fila- {suitable for "use in thispreliminary step of the ment's orotherpi oducts arefformed may 'vary present invention in conjunction with solvents Very widely; Itde'pends to someextentupjon the in the spinning solution which'are insoluble or amount of fdraW-doviimfif any, which is applied 20 substantially insoluble in water'flfor instance 'to the filaments or?other products and alsoupon 'tetra'chlorethane;chloroform,*ethyleiie eliloride, the viscosity-of the spinning solution. In most ethylene bromide, methylene chloride, and -di eases aleiigthyup to a few inches suifices to "ehlorethyleneJ Such liquids "are solvents for produce'th adv'antagesof the present-invention.

some varieties of cellulose esters or ethers, or The filaments or other products, which will 5 on the other hand become solventswitli small of -substantiallyf-the same composition as additionsof alcohols-Which will not substantially that, of the originalspinning Solution or pmy afieet the solubility of the whole in Water; "I 'hus have comparatively" siiiall amounts of solvent for'instanceinethylene chloride,"ethylene chloabstracted therefrom so that they are still 130 ride andchloroforjm for certain yarieties-of'celliquid', may be solidified by dry or wet methods 3 'luloseace'tate become" solvents withyerys'inall orbfa combination ofthe two. ln the case additions of methyl or ethyl alcohol; where of many of thewet methodsit is of advantage 'so1yentsare'usedin the spinning solutions which as descri ed iniIf. SQP atents Nos{ 1,465,294 and are miscible with water, their solubility r mis- 1,467,493'aiid British Eatents" Nos. 340,324,

" cibility may be deereasedby dissolving in the 340,325, and 343,062 try-"employ i'nrthe coag'ulat- 3 j aqiieous bath. calcium chloride, sodiuniaoetate ath 'a solvent for the cellulose derivative or other salts; preferably to a highg concentrasea to produce strongfilamehtsor other prod- 'tion', In many cases, the water miscible solvents Iu'ets. Wherefeasible the "coagulating bath may are insoluble in" paraffin oil and like liquids so be used contiguously withthe preliminary bath 40 that these may be used for this tprelirninary *of the present invention. -For instanoe one 40 stage, especially when the spinning" solution is mayrbdfloated on the" other and the filaments {made up with some water. 1 I caused to pass or down through the two The present invention, does, howeyer, include 'ityrs' of bath; "Again the filaments or other the use of baths whiohwill dissolye out some of produts" may f be solidified by dry spinning A5 thesol'ventin theis'pinning solution but 1 which methods; in which case the'y should rise or be nevertheless will leave the filaments or other fur'awnuptnrough the preliminary bath charproducts still ina liquid or substantially liquid aote'ris'tie" of the invention; For example, the state. For this purpose baths maybe used whieh preliminary bath maybe placed .at the bottom are to some extent solvents for "tlie "'liieritffin of an'upw'ai'd dry spinriingfcell "so that the the spinning solution oralternatiyelyadditions filaments pass up through the liquid and. are 50 may be made to the baths describediaboye tor then drawn up throughthe cell through which the purpose of-conferring up oiftheni solvent maybe passed an eyaporativevmedium andare "properties for-the solvent in the -s'p nin s' oliifinallyfieither wound at the. tf p goejtal en out '-tiori.- *For instanceto aqueous -baths aloohols, -'o f tnegcen and. attei 'vyards wound. "T e-con- 55 akie'titrtkole'l like acids maybe added; i" ditiofls'wbtaining in the 'drY spinning cell may filaments or other products can be drawnout ,7

to produce very fine deniers or low cross-sections. the production of such fine products, since it presents advantages even when comparatively large filaments, such as may be used for horsehair or bristles, are produced, such products having improved extensibility and tenacity.

The followingexamples illustrate the invention, but they are not to be considered as limiting it many iwayz V Example 1 An acetone soluble cellulose acetate, preferably of relatively high acetyl content, as for 7 20-25% solution.

example 56-57% (calculated as acetic acid),

which may be produced for example as described in my British Patent No. 309,201, is dissolved in tetrachlorethane so as to form a In the event that complete solution does not .occur, a small amount of alcohol may be added thereto so as to promote solution. The said spinning solution. is then spun as follows:- A coagulating bath provided with a partition across the full width thereof,

but not reaching to the bottom, is filled with tricresylphosphate up to above the level of the spinning nozzle which is adapted to spin downwards. The partition may advantageously reach to a point some three inches below the level of the spinning nozzle. Below the partition and towards the bottom of the bath is provided a suitable guide or other member round which the filaments may be passed. Spinning is then startedup in the customary manner, the filaments being carried round a guide under the partition and up out of the bath through the compartment not containing the spinning nozzle.

7 Water is then carefully run into the compartment containing the spin- 7 ning nozzle until its lower level is at a point ously. .may be carried round a suitable feed roller about 1 to 2 inches below the'spinning nozzle. The spinning may thereafter be run continu- After leaving the bath the filaments adapted to: draw them out to the required denier. .As already indicated the process of the present invention is especially adapted to produce products of ,very low denier indeed. On leaving the feed roller the filaments may .be collected in a centrifugal box or may be wound or twisted and wound in any other desired manner. The tricresyl phosphate may then be extracted from the yarn with the aid of benzene or any other suitable agent. The products obtainedhave'a high resistance to the action of hot aqueous liquids.

Example 2 A coagulating bath containing a spinning nozzle adapted to spin upwardly isprovided with a coagulating liquor consisting of of petro- The invention is however not limited to leum spirit, having a boiling point of -120 C. and 50% of ethylene dichloride. A 20-25% spinning solution of an acetone soluble cellulose acetate is then made up in ethylene dichloride containing a small amount of alcohol. Spinning is then started up in the usual manner, and after the filaments have been carried round the customary feed roller a saturated aqueous solution of common salt is run slowly and carefully into the'bottom of the bath, as for example by means of a tube or pipe reaching to the bottom, until the spinning nozzle is immersed therein to a depth of 1 to 2inches. Spinning is thereafter carried on continuously, and the filaments may, as described in Example 1, be stretched and collected in any suitable manner. Example 1 they may, while being wound or twisted andwound, be washed with benzene or with petroleum spirit.

v V Example 3 V Spinning is conducted in the apparatus described with reference to Figure 2 in British inches above the face of the spinning nozzle.

As in' Initially the cup is filled up to the level of the overflow with benzene or petroleum ether. Spinning is started up as described in the said British patent, using a spinning solution prepared according to Example 2 above, the filaments being set by a dry spinning process after passage through the hydrocarbon layer. Once spinning has started'up water is run in to the cup until the benzene or petroleum hydrocarbon has been completely displaced. Spinning is then contin ued in the. manner customary in dry spinning processes. As before the filaments may be drawn out to very fine deniers. Theymay be wound or twisted and wound, as for example by a cap spinning device. I

The filaments or other products produced according to any of the above methods may be further treated in any desired manner to impart improved properties thereto. For instance they may be stretched when in the finished condition, whether or not they have been drawn out or stretched during the formation, so as to obtain stillfurther increased strength; Again they may be treated according to the process described in my British Patent No. 359,971 with or withoutstr etching. This specification describes impregnating the materials with relatively dilute solutions of solvents or softening agents and'subsequently concentrating the solutions on the material so as to enable them to exert a solvent action thereon. Examples of suitable solvents orsoftening agents are aqueous solutions of thiocyanates, such as those of the alkalies, ammonium and alkaline earths, aqueous solutions of zinc chloride, acetic acid,

formic acid, lactic acid, diacetone alcohol, methyl or ethyl lactate, acetone, and the like; and

-monoand di-etherS or esters or ether esters mono-ethyl ether of diethylene glycol etc.; phenols, formaldehyde,;acetaldehyde, mono-, di-

and tri-acetins, dichlorethylene, and the like,

mineral acids, sulphonic or otherv organo mineral acids, or acid esters of mineral acids, or mixtures ofthese, or solvent mixtures. The

The solvent action may be exerted on the fila-' ments or other products with or without simul-- taneous stretching; i

The invention is broadly applicable to the 1 production of filaments, threads, and other products etc. from solutions .of any suitable cellulose derivatives, for example cellulose acetate or other carboxylic acid esters of cellulose, e. g. cellulose acetate, formate, propionate, butyrate cellulose nitrate, and cellulose ethers, for instance methyl, ethylor benzyl cellulose,

What I claim and desire to secure by Letters Patent is; M e

1. Process for the manufacture of filaments, yarns, threads, ribbons, films and like products from solutions of organic derivatives of cellu-' lose, comprising extruding said solutions into a liquid which is a non-solvent for the organic derivative of cellulose and is substantially a non-solvent for the solvent in the organic derivative of cellulose solution, and then leading the products from said liquid whilst they are still substantially liquid, into a setting medium.

2. Process for the manufacture of filaments,

yarns, threads, ribbons, films and like products from solutions of cellulose acetate, comprising,

extruding said solutions into a liquid which is a non-solvent for the cellulose acetate and is substantially a non-solvent for the solvent in the cellulose acetate solution, and then leading the products from said liquid whilst they are still substantially liquid, into a setting medium.

3. Process for the manufacture of filaments,

yarns, threads, ribbons, films and like products from solutions of cellulose acetate, comprising extruding solutions of the cellulose. acetate in solvents substantially immiscible with water intowater, and then leading the same from the water while the products are still substantially. V liquid into a setting medium. and the like or other esters of cellulose, e. g...

4. Process according to claim 1, wherein the 1 organic derivative of cellulose solution is caused to pass through the liquid for a comparatively short distance onfthe order of 1 to 2 inches.

5. Process according to claim 1, wherein the setting of the products is effected by wet splnsetting of the products is effected by dry spinning processes.

8'. Process according toclaim 1, wherein the products are drawn ,down to products of low 7 denier or small cross-section."

HENRY DREYFUS. 

